Liquid fuel injection pump



Dec. 2, 1952 F. M. EVANS LIQUID FUEL INJECTION PUMP 2 SHEETSSHEET 1 Filed Jan. 26, 1949 g qwu Dec. 2, 1952 F. M. EVANS 2,619,908

LIQUID FUEL INJECTION PUMP Filed Jan. 26, 1949 2 SHEETSSHEET 2 7/ A n j ii; 7*- AL? Q Fig.3

Patented Dec. 2, 1952 v UNITED PATENT "LIQUID hzfr zmon BUMP. 7

,Fraser Mackie Evans, Acton, London England,

. ,assignoi to C. A. V. Limited, Londfdn;E ngla nd -Application January 26, 1949, Serial Nu= !72-,95.4

v =1n-GreatBritain Febtuaryzg 1948 4 Claims; (Cl: 103%;38)

, t 1 a: This invention: relates I to liquid fuel injection pumps for use with internal combustion engines andzoi the- .ki=nd :havingcombined therewith the means f0r=regulating the pump output.

;:It is; already; known to provide in combination secured by thezdriverin the position in whichthe extra.::supp1y 1a'lways availab1e.-=- Such use of the BXtIaHSHpDIY :device'is undesirable;and the .objectof theipresent invention is to enable itto be prevented in a simple. andz-oonvenient manner.

The invention comprises an arrangement in which: the. manually-operablelpart and a part associated: with the normal I regulating means of the pump ar adaptedisorto interact .that'at all times onlysa. temporary extra fueLsi pplyv can be obtained. In the accompanying drawings: i Figures 1, 2 and 3 are sectional views-illustratingethree-difierent embodiments of the invention. I; -In;.Eigure. lot the drawings 7 a; indicates a slidable rack bar which is adapted to be .ahtnated manually er-automatically.to vary the output. of areci procatory pump ,A .by imparting rotational adjusting. movement to thenpum'pmplunger or phingersl (not.. shown) Such a rack banana pump arewell knownla'ndrdo hotrequire'furthejr description. .wiThe rack harea, ismovablelto the l'eft forincreasing theoutpntlof the pump, andin the opposite direction for. reducing the pumpputput. i \Inrcarrying-the invention into effect as shown inFig ure 1,"there is employed for limiting the movementiof therack bar a in the direction for increasing the'pump output, astop consisting of anabutmentbin the formof a collar which is slidable o'na fixed'lpost c; and islloaded by a spring dvtendinglto move it. in theupward direction relajtiveliysto th post by thelpostbei'ng' secured at its' lower end'toiahousingewhich forms a chamber containing the post and the adjacent; end of the rack bar a; Theisaid endiof the bar a is pro vided...with; an adjustable contact ,pie'ce 1 which .whenfir 'contact with the abutmen'tib. determines the,- normal maximum outputof the..pump. In one side .of the abutment b is formed .a' radial hole'g which when the abutmentjsrin theiposfi quired extrafuelifor s tion shown can'rherent'ered bythe suitably shaped endvof the cohtatpice. ,1 Coaxially with the upper. endhf the post therejis carriedby'the hous ing ela -pushhutton in which. is loaded by} a spring iinandnthroug'h the -.jmediurmof which the abutmentibt can bem'oved byfthe driverfiiito the posi tion shown itonbring. the hole oppositeito the .oontactpie'cejj, thejabutment being then held in.thisipositio, f-by a Qatch, or pawl .loaded By a spring "kn 'ljhev pawl i it is .jmuuntedflin a transverse hole thelpost c,:and .is such that one end ofhitlcan be pressed into the holejg by the associated spring ki'ajThelendnf the-spring is remote from theipawl '7" is supported l'balhm' which engagesalongitudinalrgroove in theiabutm'ent b for preventing rotation of the latter relatively to the post 6. ...Further the inner end of the "push button hasformedjon it a shroudn or other projection-which. can overlap the adjacent e'nd of the abutmentlii. ,The arrangement issuch that thepush button h c'an operate the abutment b only..when the. contactpiece f on thepump regulating bar ai's clear of the abutment? Otherwise .thefshi'ond'n foiils the contact piece and renders theipiishrbutton inoperative. I

V-When the; enginev is at rest, the regulating har a normallyv oocupiesifia :bosition .shown corresponding :jto the; minimum fuel s pply. *Also the pawl; j'is' out .of engagement with thehole g "in the abutment: b,; and the': latter: is held by its loadingispring d in a "position higherthan that "shown so: that the, aw1 cannot enter the said '-hole.--sccnsequently the abutment b isthen tree to be actuated by the push-huttbnJt-fbr moving the abutment to theposition which the ihole-g isnppositethe-contact-piece f and pan lie-engaged by the-- pawl-y', the gap between theiahutment and the contact piece offering no olostinotionto the: shroud n on the-push button h.--=The-abutment b-is actuated as above do scribed by the push button h prior to the" engine being started;- 'lhe parts-*nmv occupy the positionsshown. 1 On turning the engine-by aniele the motor or otherwise for starting, the;regulating bar a-is moved automaticallyby the piim'p governor -or-manua-l-1y "to the} positioh of. xi m fi ii' ply an "as 'theg nta'ctc icer n then enter. the holeg in the abutment the er a LCM], miVQJby0fi1jtnOrma1 supply; position to enables the punipgto ewe the rea x I I fiusojentering the 1 a he ntact, Pi e .fpre i' s lh l pawl ilaridis'o. di enga esii from the; abutment; theiilatterliheingvthen'held by. thf cant ctibiece againstlmovement Jon the. .postvci'lunderthe. ace

3 tion of the associated spring d, excepting for a small movement required for preventing the engagement of the pawl with the abutment when the contact piece is withdrawn. This small movement is allowed by making the operative end of the contact piece ,1 of rather smaller diameter than the hole 9. When the engine has been started and is running under its own power, the regulating bar a moves to the position for diminishing the fuel supply, and so withdraws the contact piece 1 from the hole 9, allowing the abutment b to be moved to its initial position by its spring d. When, during normal running, the bar a is moved to the position for increasing the pump output the maximum output is determined by contact of the contact piece 1 with the outer surface of the abutment b, and while the bar a is in this position any attempt by the driver to obtain the extra supply, by again pressing the push button, is prevented by the shroud n on the push button encountering the contact piece on the regulating bar and thus preventing actuation of the abutment. If the abutment c is moved by the push button it to enable the pawl 7' to engage the hole 9 at any other time while the engine is running and when the contact piece I is clear of the abutment b only a temporary extra supply is obtainable and this is of no consequence, but if the push button is operated and secured in its operative position, the shroud n then occupies such a position that it prevents the regulating bar a from moving into the normal maximum fuel position. In Figure 2 parts similar to, or serving the same purposes as, parts shown in Figure 1, are indicated by the same reference characters sufiixed by 1.

In the arrangement illustrated by Figure 2, I attach one end of the regulating bar a by means of a link 2 to one end of an arm 3 which at the other end is pivotally attached to the interior of the housing e The contact piece I is in this arrangement adjustably fixed in the closed end of the housing. On the side of the arm 3 adjacent to the contact piece f is slidably mounted an abutment b loaded by a spring d th abutment being movable against the action of the spring by the inner end of the push button h which is loaded by a spring i In this example the abutment is attached to the arm 3 by screws 5 passing through slots in the abutment. Also the regulating bar a is movable to the right for increasing the pump output. In the abutment is formed a hole 9 The abutment b is held (when depressed by the push button h by a catch or pawl 9' carried by the arm 3 and loaded by a spring k The end of the abutment on which the push button can act is situated as shown at a convenient distance from the end of the arm 3 connected to the bar a The action is similar to that above described. When the engine is at rest and the arm 3 attached to the pump regulating bar a is clear of the contact piece f and the push button can move the abutment into the position-in which the hole 9 in the bar can engagethe contact piece, so enabling the pump to give the extra supply required when starting the engine. While the engine is running, the normal maximum supply is determined by contact of the face of the abutment b with the contact piece f Moreover while the engine is running under its own power and the bar a is at or near the position of maximum supply actuation of the push button is prevented by the adjacent end of the arm 3, and at most only a temporary extra supply can be obtained as a consequence of movement of the abutment by the push button while the arm is in or near the position of minimum supply. Furthermore if the push button be secured by the driver in the depressed position the inner end of the push button prevents the arm 3 from moving under the action of the bar a to the normal maximum fuel position.

In Figure 3, which illustrates a modification of the example shown in Figure 2, parts similar to, or serving the same purposes as, parts shown in Figure 2, are indicated by the same reference characters suffixed by 2 instead of 1. I mount on one side of the arm 3 a, hollow plunger 1) which serves as the abutment and is supported at one end by a spring d the plunger being slidable in a cylindrical bore 6 formed at one side of the arm. Also a catch piece or pawl i is arranged within the plunger 1) and at one end is pivotally connected to the arm, the said end being adapted to support the spring d in a manner which enables the spring to exert a tilting action on the pawl. The outer end of the pawl 7 can engage a gapped end portion of the plunger 1) for holding the same when (as shown) it is moved by the push button b to the position in which an extra fuel supply is obtainable. On starting the engine the arm 3 is moved into a position in which the pawl 9' can abut against the contact piece f and thereby be released. Subsequently the action is similar to that above described, the upper end of the arm 3 being adapted by engagement with the inner end of the push button it to prevent a sustained extra supply of fuel from being obtained, and the normal maximum supply being determined by the interaction of the outer surface of the plunger 13 and the contact piece F. The extent of sliding movement of the plunger 1) in the bore 6 is controlled by a stop 8 on the arm 3 engaging a slot 9 in the plunger.

By this invention it becomes impossible for the driver permanently to obtain the extra supply of fuel during normal running of the engine.

The invention is not, however, restricted to the examples described, as details of construction or arrangement can be varied to suit different requirements.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a liquid fuel injection pump having means for regulating its output, the combination of an abutment and a contact piece which are arranged to co-operate with each other for limiting the movement of the regulating means in thedirection for increasing the pump output, and one of which is connected to and movable by the regulating means, a manually operable push button for moving the abutment relatively to the contact piece from a normal position in which the abutment and contact piece co-operate with each other for determining the normal maximum output of the pump to a second position in which the pump output can be increased beyond its normal maximum under the action of the regulating means, a spring for returning the abutment to its normal position, and a catch for temporarily retaining the abutment in the second position, the catch being arranged to be released by the contact piece during movement of the regulating means for increasing the pump output beyond its normal maximum, and the push button being arranged to prevent normal movement of the regulating means in the event of the push button being held down.

2. In a liquid fuel injection pump having output regulating means formed in part by a slidable bar, the combination of a contact piece carried by the slidable bar, an abutment slidable transversely to the bar and arranged to co-operate with the contact piece for limiting the movement of the regulating means in the direction for increasing the pump output, a manually operable push button arranged to overlap one end of the abutment and also to move the latter relatively to the contact piece from a normal position in which the abutment and contact piece cooperate with each other for determining the normal maximum output of the pump to a second position in which the pump output can be increased beyond its normal maximum under the action of the regulating means, a spring for returning the abutment to its normal position, and a catch for temporarily retaining the abutment in the second position, the catch being arranged to be released by the contact piece during movement of the regulating means for increasing the pump output beyond its normal maximum, and the push button being arranged so that, when depressed, it obstructs the normal movement of the regulating means.

3. In a liquid fuel injection pump having output regulating means formed in part by a slidable bar, the combination of a stationary contact piece, a pivotally mounted arm connected to the slidable bar, an abutment slidably carried by the arm and arranged to co-operate with the contact piece, for limiting the movement of the regulating means in the direction for increasing the pump output, a manually operable push button for moving the abutment relatively to the contact piece from a normal position in which the abutment and contact piece co-operate with each other for determining the normal maximum output of the pump to a second position in which the pump output can be increased beyond its normal maximum under the action of the regulating means, a spring carried by the arm for returning the abutment to its normal position, and a catch for temporarily retaining the abutment in the second position, the catch being arranged to be released by the contact piece during movement of the regulating means for increasing the pump output beyond its normal maximum, and the push button being arranged so that, when depressed, it obstructs the normal movement of the regulating means.

4. A liquid fuel injection pump according to claim 3, in which the abutment has the form of a hollow plunger, and in which the catch lies within and extends along the hollow plunger, one end of the catch being pivoted to the arm, and the spring being arranged to bias the catch towards a position in which it can engage the plunger.

FRASER MACKIE EVANS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,966,694 Vaudet et a1 July 17, 1934 1,967,101 Rassbach et al July 17, 1934 2,080,746 Schweitzer May 18, 1937 2,185,144 Edwards Dec. 26, 1939 

